APPROXIMATE COST OF SLATING, PER SQUARE ==================================+========+=========+============ | | Cost of | |Cost of | Laying, | Total Cost, Classification | Slate |Including| Exclusive |F. O. B.| Roofing |of Builder’s |Quarries|Felt, and| Profit | | Freight | ----------------------------------+--------+---------+------------ _Black Slate_ | | | Brownville, Maine | $8.00 | $5.00 | $13.00 Monson, Maine | 7.00 | 5.00 | 12.00 Peach Bottom, Pennsylvania | 5.50 | 4.00 | 9.50 Chapman (Hard Vein), Pennsylvania | 4.50 | 3.50 | 8.00 Bangor, Pennsylvania | 4.50 | 3.50 | 8.00 Lehigh, Pennsylvania | 4.00 | 3.50 | 7.50 Buckingham, Virginia | 3.75 | 4.00 | 7.75 _Red Slate_ | | | Vermont | 12.00 | 4.25 | 16.25 _Green Slate_ | | | Vermont | 5.50 | 4.25 | 9.75 _Purple Slate_ | | | Vermont | 5.00 | 4.25 | 9.25 _Mottled Slate_ | | | Vermont (Purple and Green) | 4.00 | 4.25 | 8.25 ==================================+========+=========+============ =59. Sheet-Metal Roofs.=—In estimating sheet-metal roofs, the hips and valleys are measured extra their entire length by 1 foot in width, to compensate for increased labor and waste of material in cutting and laying. Gutters and conductor pipes, or leaders, are measured by the linear foot, 1 foot extra being added for each angle. All flashings and crestings are measured by the linear foot. No deductions are made for openings (chimneys, skylights, ventilators, or dormer-windows) if they are less than 50 square feet in area; if between 50 and 100 square feet, one-half the area is deducted; if over 100 square feet, the whole opening is deducted. An extra charge is made for labor and waste of material to flash around openings. =60.= There are two regular sizes of roofing plates, namely, 20 in. × 28 in. and 14 in. × 20 in. The larger size is generally used on common work, owing to the fact that it requires fewer seams on the roof and consequently cheapens the cost of laying. A third size, namely, 10 in. × 20 in., is also supplied, and is used generally for gutters and leader pipes. Sheets 10 in. X 14 in. are sometimes used for laying roofs, as they can be cleated better than the larger sizes. Such small sheets, however, cost more to lay.